add: modrinth client and check command

6 files changed, 247 insertions, 7 deletions

diff --git a/internal/cli/check.go b/internal/cli/check.go
new file mode 100644
index 0000000..1df5137
--- /dev/null
+++ b/internal/cli/check.go
@@ -0,0 +1,100 @@
+package cli
+
+import (
+	"fmt"
+
+	tea "github.com/charmbracelet/bubbletea"
+	"github.com/charmbracelet/lipgloss"
+
+	"github.com/hachem-wtf/benson/internal/config"
+	"github.com/hachem-wtf/benson/internal/modrinth"
+)
+
+type compatMod struct {
+	slug     string
+	filename string
+}
+
+type checkResult struct {
+	compatible   []compatMod
+	incompatible []string
+	failed       []string
+}
+
+func runCheck(m *model) tea.Cmd {
+	m.busy = true
+	cfg := m.cfg
+	return tea.Batch(m.spin.Tick, func() tea.Msg {
+		return outputMsg{text: checkReport(cfg)}
+	})
+}
+
+func checkReport(cfg *config.Config) string {
+	client := modrinth.NewClient()
+	var res checkResult
+
+	for _, slug := range cfg.ModrinthMods {
+		versions, err := client.GetVersions(slug)
+		if err != nil {
+			res.failed = append(res.failed, slug)
+			continue
+		}
+
+		match := modrinth.CompatibleVersion(versions, cfg.MinecraftVersion, "fabric")
+		if match == nil {
+			res.incompatible = append(res.incompatible, slug)
+			continue
+		}
+
+		filename := match.VersionNumber
+		if len(match.Files) > 0 {
+			filename = match.Files[0].Filename
+		}
+		res.compatible = append(res.compatible, compatMod{slug: slug, filename: filename})
+	}
+
+	return renderCheck(cfg, res)
+}
+
+func renderCheck(cfg *config.Config, res checkResult) string {
+	rows := []string{
+		headingStyle.Render(fmt.Sprintf("Compatibility · MC %s · Fabric", cfg.MinecraftVersion)),
+		"",
+	}
+
+	if len(res.compatible) > 0 {
+		rows = append(rows, successStyle.Render("Compatible"))
+		for _, c := range res.compatible {
+			rows = append(rows, "  "+successStyle.Render("✓ ")+c.slug+mutedStyle.Render(" → "+c.filename))
+		}
+		rows = append(rows, "")
+	}
+
+	if len(res.incompatible) > 0 {
+		rows = append(rows, errorStyle.Render("No compatible version"))
+		for _, slug := range res.incompatible {
+			rows = append(rows, "  "+errorStyle.Render("✗ ")+slug)
+		}
+		rows = append(rows, "")
+	}
+
+	if len(res.failed) > 0 {
+		rows = append(rows, warnStyle.Render("Failed to check"))
+		for _, slug := range res.failed {
+			rows = append(rows, "  "+warnStyle.Render("! ")+slug)
+		}
+		rows = append(rows, "")
+	}
+
+	total := len(cfg.ModrinthMods)
+	ok := len(res.compatible)
+	rows = append(rows, mutedStyle.Render(fmt.Sprintf("Summary: %d/%d mods compatible", ok, total)))
+
+	if len(res.incompatible) == 0 && len(res.failed) == 0 {
+		rows = append(rows, successStyle.Render("Safe to generate."))
+	} else {
+		rows = append(rows, warnStyle.Render("Not all mods are compatible — generate may have issues."))
+	}
+
+	return lipgloss.JoinVertical(lipgloss.Left, rows...)
+}
diff --git a/internal/cli/cli.go b/internal/cli/cli.go
index 4e394e6..6609a7e 100644
--- a/internal/cli/cli.go
+++ b/internal/cli/cli.go
@@ -101,6 +101,9 @@ func (m *model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		return m, tea.Println(msg.text)
 
 	case spinner.TickMsg:
+		if !m.busy {
+			return m, nil
+		}
 		var cmd tea.Cmd
 		m.spin, cmd = m.spin.Update(msg)
 		return m, cmd
diff --git a/internal/cli/commands.go b/internal/cli/commands.go
index 1f1f132..cf7cc90 100644
--- a/internal/cli/commands.go
+++ b/internal/cli/commands.go
@@ -20,6 +20,11 @@ func defaultCommands() []command {
 			},
 		},
 		{
+			name: "check",
+			desc: "Check whether the configured mods are compatible",
+			run:  runCheck,
+		},
+		{
 			name: "help",
 			desc: "Show available commands",
 			run: func(m *model) tea.Cmd {
@@ -30,15 +35,19 @@ func defaultCommands() []command {
 }
 
 func welcomeBlock(cfg *config.Config, version string) string {
+	header := lipgloss.JoinHorizontal(
+		lipgloss.Bottom,
+		titleStyle.Render("BENSON"),
+		subtitleStyle.Render("  v"+version),
+	)
+
 	inner := lipgloss.JoinVertical(
 		lipgloss.Left,
-		titleStyle.Render("BENSON"),
-		subtitleStyle.Render("a Minecraft server manager from hell"),
-		"",
-		mutedStyle.Render(fmt.Sprintf("Fabric · MC %s · v%s", cfg.MinecraftVersion, version)),
+		header,
+		mutedStyle.Render("Fabric · MC "+cfg.MinecraftVersion),
 	)
 
-	hint := mutedStyle.Render("Type a command below. Tab autocompletes · Ctrl+C quits.")
+	hint := mutedStyle.Render("Tab autocompletes · Ctrl+C quits")
 
 	return lipgloss.JoinVertical(lipgloss.Left, bannerStyle.Render(inner), "", hint)
 }
diff --git a/internal/cli/styles.go b/internal/cli/styles.go
index c0a61e5..78d5cb4 100644
--- a/internal/cli/styles.go
+++ b/internal/cli/styles.go
@@ -14,7 +14,7 @@ var (
 	bannerStyle = lipgloss.NewStyle().
 			Border(lipgloss.RoundedBorder()).
 			BorderForeground(colPrimary).
-			Padding(0, 3)
+			Padding(0, 2)
 
 	titleStyle    = lipgloss.NewStyle().Bold(true).Foreground(colPrimary)
 	subtitleStyle = lipgloss.NewStyle().Foreground(colMuted)
diff --git a/internal/modrinth/modrinth.go b/internal/modrinth/modrinth.go
new file mode 100644
index 0000000..8060f3b
--- /dev/null
+++ b/internal/modrinth/modrinth.go
@@ -0,0 +1,128 @@
+package modrinth
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"time"
+)
+
+const (
+	apiBase   = "https://api.modrinth.com/v2"
+	userAgent = "benson/2.0 (github.com/hachem-wtf/benson)"
+)
+
+type File struct {
+	URL      string `json:"url"`
+	Filename string `json:"filename"`
+	Primary  bool   `json:"primary"`
+}
+
+type Version struct {
+	ID            string    `json:"id"`
+	VersionNumber string    `json:"version_number"`
+	DatePublished time.Time `json:"date_published"`
+	GameVersions  []string  `json:"game_versions"`
+	Loaders       []string  `json:"loaders"`
+	Files         []File    `json:"files"`
+}
+
+type Client struct {
+	http *http.Client
+}
+
+func NewClient() *Client {
+	return &Client{http: &http.Client{Timeout: 30 * time.Second}}
+}
+
+func (c *Client) GetVersions(slug string) ([]Version, error) {
+	url := fmt.Sprintf("%s/project/%s/version", apiBase, slug)
+
+	req, err := http.NewRequest(http.MethodGet, url, nil)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("User-Agent", userAgent)
+
+	resp, err := c.http.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("modrinth: %s returned %s", slug, resp.Status)
+	}
+
+	var versions []Version
+	if err := json.NewDecoder(resp.Body).Decode(&versions); err != nil {
+		return nil, err
+	}
+	return versions, nil
+}
+
+func LatestVersion(versions []Version) *Version {
+	if len(versions) == 0 {
+		return nil
+	}
+
+	best := 0
+	for i := 1; i < len(versions); i++ {
+		if versions[i].DatePublished.After(versions[best].DatePublished) {
+			best = i
+		}
+	}
+	return &versions[best]
+}
+
+func CompatibleVersion(versions []Version, mcVersion, loader string) *Version {
+	var compatible []Version
+	for _, v := range versions {
+		if !contains(v.GameVersions, mcVersion) {
+			continue
+		}
+		if loader != "" && !contains(v.Loaders, loader) {
+			continue
+		}
+		compatible = append(compatible, v)
+	}
+	return LatestVersion(compatible)
+}
+
+func (c *Client) Download(url, dest string) error {
+	req, err := http.NewRequest(http.MethodGet, url, nil)
+	if err != nil {
+		return err
+	}
+	req.Header.Set("User-Agent", userAgent)
+
+	resp, err := c.http.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("download: %s returned %s", url, resp.Status)
+	}
+
+	f, err := os.Create(dest)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	_, err = io.Copy(f, resp.Body)
+	return err
+}
+
+func contains(list []string, s string) bool {
+	for _, item := range list {
+		if item == s {
+			return true
+		}
+	}
+	return false
+}
diff --git a/main.go b/main.go
index cc8d4ed..dfe0d7f 100644
--- a/main.go
+++ b/main.go
@@ -8,7 +8,7 @@ import (
 	"github.com/hachem-wtf/benson/internal/cli"
 )
 
-const version = "1.1.0"
+const version = "2.0"
 
 func usage() {
 	fmt.Fprint(os.Stderr, `benson — a Minecraft server manager from hell